2-aryl-1, 3-di(4-pyridyl)-2-propanols



United States Patent 3,410,859 Z-ARYL-1,3-DI(4-PYRIDYL)-2-PROPANOLSBernard Brust, Parsippany, Troy Hills, Rodney Ian Fryer, North Caldwell,and Leo Henryk Sternbach, Upper Montclair, N.J., assignors toHolfmann-La Roche Inc.,

Nutley, N.J., a corporation of New Jersey No Drawing.Continuation-impart of application Ser. No.

465,764, June 21, 1965. This application June 28, 1967, Ser. No. 649,477

17 Claims. (Cl. 260--294.8)

ABSTRACT OF THE DISCLOSURE Novel pharmacologically active 2aryl-1,3-di(4-pyridyl)-2propanols are prepared inter alia by thereaction of a picolyl metal compound and a benzoyl halide or a benzoicacid ester.

RELATED APPLICATIONS This application is a continuation-in-part ofapplication Ser. No. 465,764 filed June 21, 1965, which is in turn acontinuation-in-part of application Ser. No. 344,198 filed Feb. 12,1964, now abandoned, said application Ser. No. 344,198 being in turn acontinuation-in-part of application Ser. No. 266,029 -filed Mar. 18,1963, now abandoned.

DETAILLED DESCRIPTION This invention relates, in general, to novelcompounds and to processes for producing same. More particularly, theinvention relates to pharmacologically active pyridyl compounds and toprocesses for their manufacture.

The compounds of this invention have the formula as follows:

Additionally, the invention includes salts of the Formula 1 compoundswith medicinally acceptable acids such as hydrochloric acid, sulfuricacid, nitric acid, p-toluene sulfonic acid, etc. The compounds ofFormula I as well as the acid addition salts thereof relieve or diminishtremors which are brought about in animals by Tremorine, i.e., 1,4di-pyrrolidino Z-butyne, with a minimum of peripheral anti-cholinergicside elfects. Additionally, they reduce hypothermia produced byTremorine. Thus, the compounds are indicated for use in the study of thetreatment of tremors which are characteristic of Parkinsons disease.

For example, the compounds of this invention when administered orally toanimals such as mice relieve Tremorine-induced tremors in single doseamounts ranging between about 7 and about mg./kg. By way ofillustration, the compound 2-phenyl-1,3-di(4-pyridyl)-2-propan0l whichhas an LD of 2.8 grams/kg. orally in. mice exhibits activity in theanti-Tremorine test when administered at a single oral dose of 7.1m-g./kg. The anti-Tremorine test employed in determining anti Pankinsonactivity was carried out as follows:

Six mice of both sexes weighing 17 to 22 grams were employed per doselevel. The test compounds were administered orally and one-half hourlater 20 ting/kg. of Tremorine was administered intraperitoneally. TheTremorine-treated mice were observed for 30 minutes. Animals notexhibiting tremors within this time were considered protected. The ED iscalculated by the method of Miller and Tainter (Proc. Soc. Exptl. Biol.Med, volume 57, page 261, 1944).

As a further illustration of the anti-Tremorine activity of thecompounds of this invention other exemplary compounds were active in theabove-described test as follows:

so Compound: (mg/kg.) 1,3-di (4-pyridyl -2- (p-tolyl -2-propanol 30 2 (2fluorophenyl) 1,3-di(4-pyIidyl)-2-propanol 6.7

2 (3 fluorophenyl) 1,3-di(4-pyridyl)-2-propanol 7.8

2 (4 chlorophenyl) 1,3-di(4-pyridyl)-2-propanol 38 2 (4 fluorophenyl)1,3-di(4-pyridyl)-2-pro panol 16.5

2 (4 methoxyphenyl) 1,3 di(4-pyridyl)-2- propanol 2 (3 bromophenyl)1,3-di(4-pyridyl) 2- propanol 26.5 1,3 di(4 pyridyl)2-(o-tolyl)-2-propanol 70 By way of comparison the known anti-Parkinsonagent a cyclohexyl a-phenyl-l-piperidine propanol exhibits activity inthe above-described anti-Tremorine test at an oral dose of about 19rug/kg.

The compounds of this invention have also demonstrated high potency andlong duration of action in reducing hypothermia induced by Tremorine inmice. The efiectiveness of the compounds of this invention againstTremorine-induced hypothermia in mice was determined by administeringTremorine intraperitoneally to mice at a level of 5 mg/ kg. Rectaltemperatures were taken before treatment and after treatment. Testcompounds were ad ministered orally and the Tremorine was adminstered15, 45, 105, 165, 225 and 285 minutes later. The temperatures were thentaken 15 minutes following administration of the Tremorine. Six micewere used for Tremorine control effects during the tests and 16 micewere used for each.- compound at each test interval. Activity wasdetermined by calculation of the percent protection by drawing activitylines on graph paper using the method of least squares. The results forillustrative compounds of this invention are given below. For comparisonthe activity of the known anti-Parkinson agenta-cyclohexyl-a-phenyl-lpiperidine propanol when tested by the samemethod is also given.

PERCENT PROTECTION AGAINST HYPOTHERMIC EFFECTS OF TREMORINE Dose (mg/kg.Percent Protection .0. p 0.5 III. 1 hr. 2 hr. 3 hr. 4 hr 5 hr2(4-methylmercaptophenyl)-1,3-di(4pyridyD-2-propanol 30 98.0 87. 6 66. 946. 2 25. 5 4. 8 2-(4-methoxypheny1)-1,3-di-(4-pyridyD-2pr0pan0l 30 97.1 90. 2 83. 2 76. 3 69. 3 a-eyclohexyl-a-phenyl-l-piperidine propane] 3096. 1 91. 9 83. 4 74. 9 66. 5 58 Thus, the compounds of this inventionhave demonstrated pharmacological effects in warm blooded animalsqualitatively similar in many respects to those of Bt-CYCIO-hexyl-ot-phenyl-l-piperidine propanol, well-known for its therapeuticuses and properties.

Furthermore, the compounds of this invention alter the activity of theliver microsimal drug metabolizing enzymes. For example, they inhibitthe following enzymatic oxidative reactions: hexabarbital toketohexobarbital, acetanilid to p-hydroxyacetanilid, amphetamine tophenylacetone, dilantin to its p-hydroxy derivatives, etc. On prolongedadministration the compounds of this invention stimulate the activity ofthe liver microsomal drug metabolizing enzymes. Because of theiractivity, these compounds provide a valuable tool for the study of thedrug metabolizing enzyme systems associated with the liver microsomesand are useful in the study and treatment of diseases caused bymetabolic failures of such enzyme systems, for example, in the treatmentof phenylketonuria.

The activity of the compounds of this invention in altering the livermicrosimal drug metabolizing enzymes was first established by in vitroexperiments on rat liver microsomal enzyme fractions carried out asfollows:

Male albino rats of the Charles River strain weighing between 150 and250 grams were sacrificed by cervical dislovation and the livers were'quickly removed and placed on cracked ice. The livers were weighed and a112 (w./v.) homogenate in 0.1 molar sodium phosphate, pH 7.4, wasprepared in an ice-cooled Waring blendor. The liver was homogenized fora period of about thirty seconds and the resulting homogenate wascentrifuged at 1,000 times gravity for a period of thirty minutes at atemperature of C. in an international refrigerated centrifuge, modelER-2. The supernatant was further centrifuged at 9,000 times gravity fora period of twenty minutes, at a temperature of 0 C. in a Spinco model Lultracentrifuge. The supernatant fraction, which contained themicrosomes and the soluble cellular material, was used in the studyhereinafter described.

In the study a reaction mixture was prepared using 2 ml. of the enzymefraction obtained as described in the preceding paragraph, a substrateof 0.5 ml. of sodium hexobarbital, 1.0 ml. of a solution containing 2moles of triphosphopyridine nucleotide and 20 ,umoles of glucose-6-phosphate disodium salt, 40 moles of nicotinamide hydrochloride and 20moles magnesium chloride, 0.5 ml. of a compound of Formula I and themixture was adjusted to a final volume of 5.0 ml. with 0.1 molar sodiumdihydrogen phosphate buffer, pH 7.4. In the preparation of this reactionmixture, the ingredients, except the substrate, i.e., sodiumhexobarbital, and the inhibitor, i.e., a compound of Formula I, werepreincubated for a period of about fifteen minutes at a temperature ofabout 37 C. under a mixture of 95 percent oxygen5 percent carbondioxide, After the addition of the substrate and inhibitor, the mixturewas incubated for a period of about fifteen minutes under the sameconditions. The reaction was terminated by placing 3 ml. of theincubation tube containing ml. of hexane (washed with 0.5 volume of 0.1molar sodium dihydrogen phosphate buffer, pH 5.5), 1.5 grams of sodiumchloride and 1.0 ml. of 0.1 molar sodium dihydrogen phosphate buffer(washed with 2 volumes of heptane), pH 5.5.

In each experiment a zero time tube and a blank tube were run. The zerotime tube was prepared as follows: One ml. of a solution containing 2moles of triphosphopyridine nucleotide, 20 moles of glucose-6-phosphatedisodium salt and 20 moles of magnesium chloride were incubated for aperiod of fifteen minutes with 2 ml. of enzyme and 1.5 ml. of 0.1 molarsodium dihydrogen phosphate buffer, pH 7.4. An aliquot of 2.7 ml. of theincubation mixture and 0.3 ml. of substrate was added to a centrifugetube containing the heptane extraction mixture described heretofore. Theblank tube was prepared in the same way as the zero time tube exceptthat 2.0 ml. of buffer was used. The blank tube was preincubated for aperiod of about fifteen minutes and incubated for a period of aboutfifteen minutes.

The hexobarbital was extracted by vigorously shaking the reactionmixture containing the heptane, sodium chloride and buffer for a periodof about forty-five minutes in an International Bottle shaker, followingwhich it was centrifuged at 1,000 times gravity for a period of abouttwenty minutes at a temperature of about 20 C. The supernatant (heptane)was removed with a 10 ml. pipette, with a suction bulb attached, and itwas placed in another 50 ml. ground glass stoppered centrifuge tubecontaining 5.0 ml. of 0.1 molar sodium dihydrogen phosphate buffer(washed with 2 volumes of heptane) of pH 5.5. The tubes were shaken byhand for a period of about fifteen seconds and then allowed to standuntil the phases separated. Fifteen ml. of the resulting supernatant wasplaced in a 50 ml. ground glass stoppered centrifuge tube and 4 ml. of0.8 molar sodium monohydrogen phosphate, pH 11 (adjusted with 5.0 molarsodium hydroxide), was added and the tubes were shaken for a period ofabout three minutes on the International Bottle shaker. Aftercentrifuging the tubes for a period of about three minutes at 1,000times gravity, the buffer phase was removed with a 5 ml. pipette andtransferred to a silica cuvette. The absorbency of the solution at 245nm was read in a Beckman D.U. spectrophotometer against a blankcontaining the pH buffer. A standard solution of sodium hexobarbital (20g./ml.) was used. The absorbance of this solution was about 0.590.

From the absorbancy data thus obtained there was calculated the extentto which the compounds of Formula I inhibited the oxidation ofhexobarbital by the rat liver microsomal enzyme fraction. The resultsfor illustrative compounds are as follows:

A group of five mice were injected with 2-phenyl-1,3-di(4-pyridyl)-2-propanol (100 mg./kg., i.p.) for ten successive days.Five control mice were given saline each day. Twenty-four hours afterthe last injection the mice were given DL-phenylalanine-3-C(4,4LC/IDOUS6, i.p.). Four hours later the mice were sacrificed andtheir livers were extirpated. An alcoholic liver extract was preparedand an aliquot of this material was placed on paper and chromatographedin a system which clearly separates phenylalanine from tyrosine. Theamino acid spots were identified with ninhydrin, cut out and elutedfrom'the paper with 50 percent ethanol. The radioactivity of the eluateswere counted and the percent conversion of phenylalanine to tyrosine wascalculated. In two separate experiments the mice treated with2-phenyl-1,3-di(4- pyridyl)-2-propanol synthesized 2.2 and 2.8 timesmore tyrosine than the control.

In another set of experiments rats were injected with2-phenyl-1,3-di(4-pyridyl)-2-propanol (100 mg./kg./day, i.p.) for fourdays. On the fifth day the treated and control rats were sacrificed andtheir livers were extirpated. A supernatant fraction was obtained bycentrifuging the liver homogenate at 9000 g. The enzyme fraction fromthe control and treated rats was incubated in a medium containing a TPNHgenerating system, oxygen and radioactive phenylalaine. After 1 hour ofincubation the radioactive phenylalanine and tyrosine were isolated bypaper chromatography and counted. The synthesis of tyrosine fromphenylalanine was stimulated percent and 58 percent, respectively, intwo separate experiments. This effect has been confirmed clinically asshown by clinical results in the examples appended hereto.

in which the symbol M represents an alkali metal such as sodium,potassium or lithium and is reacted with a compound having the formula CO-Hal in which the symbol X represents a hydrogen atom, a halogen atom,a lower alkyl group, i.e., an alkyl group having from 1 to 6 carbonatoms, a lower alkoxy group or a lower alkyl mercapto group; and inwhich Hal represents a halogen atom.

As the Formula III(a) compound, one can use, for example, benzoylchloride, a halogen-substituted benzoyl chloride, such as3-fiuorobenzoyl chloride, 4-fluorobenzoyl chloride, 4-chlorobenzoylchloride, etc., or a lower alkyl-substituted benzoyl chloride, such asp-toluoyl chloride, etc., an alkoxy, for example, methoxy, substitutedbenzoyl chloride or a lower alkyl-, for example, methyl,mercapto-substituted benzoyl chloride. Halides, other than chlorides,can be used, if desired.

In an alternate process, the picolyl metal compound of Formula II isreacted with a compound having the formula:

COOR

X III (b) in which the symbol R represents a lower alkyl group,

i.e., an alkyl group having from 1 to 6 carbon atoms,

such as, a methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl orhexyl group or a benzyl group; and in which the symbol X has the samemeaning as in Formula III(a).

As the Formula III(b) compound one can use an alkyl ester of benzoicacid, such as, methyl benzoate, ethyl benzoate, etc.; an alkyl ester ofan alkyl substituted benzoic acid, such as, .a methyl ester of toluicacid, an ethyl ester of toluic acid; an alkyl ester of a halogensubstituted benzoic acid, such as, methyl chlorobenzoate, ethylcholobenzoate, methyl fiuorobenzoate, ethyl fluorobenzoate, etc.; benzylbenzoate, a benzyl ester of an alkyl-substituted benzoic acid, such as,a benzyl ester of toluic acid; a benzyl ester of a halogenated benzoicacid, such as, benzyl chlorobenzoate, benzyl fluorobenzoate; an alkylester of a lower alkoxy, e.g. methoxy substituted benzoic acid; an alkylester of an alkyl-, e.g. methyl, mercapto substituted benzoic acid; abenzyl ester of a methoxy substituted benzoic acid; or a benzyl ester ofa methyl mercapto benzoic acid.

In a third process for producing the compounds of this invention, acompound ofFormula II is reacted with phenyl benzoate, or with a loweralkyl-substituted phenyl benzoate, a halogen-substituted phenylbenzoate, an alkoxy substituted, e.g., methoxy substituted, phenylbenzoate or an alkyl, e.g., methyl, mercapto phenyl benzoate. Thus, forexample, there can be used phenyl methyl-benzoate, phenylethyl-benzoate, phenyl propyl-benzoate, phenyl chloro-benzoate, phenylbromo-benzoate,

III(a) d phenyl methoxy-benzoate, phenyl methyl-mercapto-benzoate, etc.,as a starting material in such process.

In still another process for producing the compounds of Formula I, a4-picolyl magnesium bromide is reacted with phenyl benzoate or with aphenyl ester of an alkylsubstituted-, halogen-substituted-,alkoxy-substituted or alkyl mercapto-substituted benzoic acid of thetype named in the preceding paragraph.

In carrying out each of the foregoing processes, there is usedpreferably a ratio of at least about 2.0 moles of the 4-picolyl metalcompound of Formula II, or 4-picolyl magnesium bromide, for each mole ofone of Formula III compounds, or phenyl benzoate or substituted phenylbenzoate, employed. A larger or smaller quantity of the 4-picolyl metalcompound can be used, however, if desired.

The various processes described heretofore are carried out, in general,in a similar manner. In a first step, an organic solvent solution of the4-picolyl metal compound, of 4-pic0lyl magnesium bromide, is firstprepared. In general, any organic solvent in which the 4-picolylcompound is soluble, and which is inert under the reaction conditionsemployed, can be used in preparing this solution. Solvents which aresuitable for use in the practice of this invention include, for example,benzene, diethyl ether, toluene, 4-picoline, tetrahydrofuran and thelike. Mixtures of these solvents can be used, if desired.

The organic solvent solution of the 4-picoly1 metal compound, which isdescribed in the preceding paragraph, is thereafter, cooled by someappropriate means to a temperature below room temperature. In thepreferred embodiment of the invention, this solution is cooled to atemperature of about 0 C. or lower. Preferably, the solution of the4-picolyl metal compound is cooled to a temperature within the range offrom about 10 C. to 60 C. thereafter, the Formula IIE reactant, or theunsubstituted or substituted phenyl benzoate reactant, dissolved in asuitable solvent, is added to the cooled solution of the 4-picolylcompound. In preparing the solution containing the Formula III compound,or the phenyl benzoate compound, one can use any solvent in which thatcompound is soluble and which is inert under the reaction conditionsemployed. Such solvents include, for example, ethyl ether, n-butylether, dioxane, tetrahydrofuran, etc., either alone or in admixture withsome other organic solvent which is inert under the reaction conditionsemployed.

During the step of mixing the reactants, the reaction mixture should bemaintained at a relatively low temperature. For best results, thereaction mixture should be maintained at a temperature below about 0 C.,preferably at a temperature within the range of from about l0 C. to 60C. After the step of mixing the reactants has been completed, thereaction mixture is stirred, while continuously cooled, until thereaction has been completed. In general the reaction can be brought tocompletion by stirring the reaction mixture first for a period of aboutone hour at a low temperature, for example, at a temperature within therange of from about -10 C. to 60 C. and, thereafter, for an additionalperiod of about one hour at room temperature. When the reaction iscomplete, the reaction mixture is Worked up, by appropriate and suitablemeans, to isolate the pyridyl compound thus produced. The crude product,in turn, can be purified by conventional means. Methods of working upthe reaction mixture to isolate the reaction product therefrom, as wellas methods for purifying those products, will be readily apparent topersons skilled in the art. Examples for specific procedures andtechniques which are useful in accomplishing this will be found in theexamples which follow hereinafter.

As indicated heretofore, the compounds of this invention are useful,inter alia, in the study and treatment of diseases caused by metabolicfailures of enzyme systems. The manner in which they are used for suchpurpose will be readily apparent to persons skilled in the art. Ingeneral, the compounds can be formulated, with conventional inertadjuvants, into dosage forms suitable for oral or parenteraladministration. Such dosage forms include tablets and capsules as wellas solutions and suspensions. Specific examples showing the embodimentof the present compounds in particular dosage forms will be found in theexamples which follow hereinafter. The frequency of administration isvariable, depending upon the needs and requirements of the patient.

For a fuller understanding of the nature and objects of this invention,reference may be had to the following examples which are given merely asfurther illustrations of the invention and are not to be construed in alimiting sense.

Example 1 An ether-benzene solution of 1.89 liters containing 3.5 molesof phenyl lithium was added, over a 3 /2 hour period, to a stirringsolution of 326 grams of 4-picoline (3.5 moles) in 800 ml. oftetrahydrofuran. This addition was carried out in an atmosphere of drynitrogen. When the addition of the phenyl lithium solution to the4-picoline solution was completed, the reaction mixture was stirred foran additional 15 minutes. The reaction mixture was then cooled to atemperature of about 20 C. There was thus produced picolyl lithium.

A mixture of 197 grams of benzoyl chloride (1.4 mole) and 100 ml. oftetrahydrofuran was added to the picolyl lithium solution, produced asdescribed in the preceding paragraph, over a fifty-minute period. Duringthis addition, the temperature of the reaction mixture was maintained atabout 20 C. A pale green colored reaction mixture was obtained and itwas stirred at a temperature of about 20 C. for a period of about sixtyminutes. Thereafter, the reaction mixture was brought to about roomtemperature, at which temperature the mixture was stirred for a periodof about sixty minutes. Subsequently, 100 ml. of water was added to thereaction mixture in a dropwise manner. The reaction mixture was thendiluted with 1 liter of water, stirred vigorously and transferred to aseparatory funnel. In this vessel, the reaction mixture was acidifiedusing 800 ml. of 6 N hydrochloric acid. The acid layer was separatedfrom the organic phase and the latter was extracted two times, using 200ml. of 3 N hydrochloric acid each time. The acid extracts were combined,washed first three times using 500 ml. of toluene each time, and,subsequently, one time using 500 ml. of ether. Subsequently, kg. of icewas added to the acid extracts which were then made alkaline usingammonium hydroxide. During this step, the acid extracts were maintainedat a temperature of about 10 C.

Treatment of the acid extracts with alkali, as described in thepreceding paragraph, resulted in the formation of a precipitate. Thisprecipitate was recovered by filtration, following which it was washedfive times using 1.0 liter of water each time. The precipitate was thenpartitioned between 400 ml. of methylene chloride and 600 ml. of waterand the mixture was thoroughly shaken. The insoluble residue was removedby filtration and washed two times using 200 ml. of water each time.Thereafter, the residue was washed two times using 200 ml. of methylenechloride each time and one time using 200 ml. of ether. The product wasthen dried in a vacuum oven at a temperature of 50 C. Hg) for a periodof about 15 hours. There was obtained by this procedure, 2-phenyl-1,3-di(4-pyridyl)2-propanol melting first at 92 to 99 C., resolidifyingand melting again at 166 to 168 C.

Example 2 To a stirring solution of 0.5 mole of 4-picolyl lithium cooledto a temperature within the range of from 30 C. to '50 C., there wasadded 0.2 mole of p-toluoyl chloride dissolved in about 100 ml. oftetrahydrofuran. Addition of the p-toluoyl chloride to the 4-picolyllithium was accomplished under an atmosphere of dry nitrogen in adropwise fashion over a period of about sixty minutes.

The reaction mixture was allowed to stir overnight, following which itwas diluted by the addition of ml. of water. The reaction mixture wasextracted three times using 150 ml. of 6 N hydrochloric acid each time.The acid extracts were collected, combined and washed three times using150 ml. of ether each time. Thereafter, the desired product wasliberated by stirring the reaction mixture with a mixture of 500 gramsof ice and 300 ml. of ammonium hydroxide. During this step of theprocess, ice was added, as needed, to maintain the temperature at about0 C.

The precipitate which formed in this step was recovered by filtration inthe form of a brown semi-solid. The precipitate was partitioned between300 ml. methylene chloride and 300 ml. of water. The undissolved productwas recovered by filtration yielding1,3-di(4-pyridyl)-2-(ptoly)-2-propanol. Upon recrystallization of theproduct three times from an acetone-water mixture, there was obtainedthe 1,3 di(4 pyridyl) 2-(p-tolyl)-2-propanol as colorless plates,melting point at 100 C. to C., resolidifying and melting again at 160 C.to 161 C.

Example 3 In this example, 2-(3-fluorophenyl)-1,3-di(4-pyridyl)-2-propanol was prepared by the process described in the preceedingexample using 3-fluorobenzoyl chloride in place of p-toluoyl chloride.

In this procedure, after the reaction mixture had been extracted withacid and the desired product liberated, as a precipitate, by stirringthe acid extracts with concentrated ammonium hydroxide, the mixture wasfiltered given a red semi-solid product. Vigorous stirring of thisproduct with 300 ml. of water and 200 ml. of methylene chloride,followed by filtration and three crystallizations from an acetone-watermixture, yielded 2-(3-fluorophenyl)-1,3-di(4-pyridyl)-2-propanol,melting first at 108 to 112 C., resolidifying and melting again at 189to 191 C.

Example 4 In this example, 2-(4-fluorophenyl)-l,3-di(4pyridyl)-2-propanol was prepared by the process described in Example 2 using4-fluorobenzoyl chloride in place of ptoluoyl chloride.

The precipitate, which was obtained by treating the acid extracts withconcentrated ammonium hydroxide, was recovered by filtration and stirredvigorously with 40 ml. of methylene chloride and 400 ml. of water.Filtration of this mixture yielded 2-(4-fluorophenyl)-1,3-di(4-pyridyl)-2-propanol in the form of colorless crystals.Recrystallization of this product, from an acetone-water mixture,yielded the compound in the form of colorless plates, melting first at122 to 125 C., resolidifying and melting again at 155.5 to 157 C.

Example 5 In this example, a solution of 35.0 grams (0.2 mole) ofp-chlorobenzoyl chloride in 25 ml. of anhydrous tetrahydrofuran wasadded, slowly, over a period of about twenty minutes to a stirring 0.5molar solution of 4-picolyl lithium. During this addition, the reactionmixture was maintained at a temperature of about 20 C. When thisaddition was completed, the reaction mixture was stirred at atemperature of about 20 C. for a period of about thirty minutes,following which it was stirred at room temperature for an additionalsixty-minute period. Thereafter, 800 ml. of water was added to thereaction mixture, following which the mixture was made acid using 3 Nhydrochloric acid. The layers, which were thus formed, were separatedand the organic phase was extracted two times, using 200 ml. of 3 Nhydrochloric acid each time. The acid layers were combined, washed threetimes using 300 ml. of ether each time, made alkaline with 10 N sodiumhydroxide solution and diluted to a volume of 4.0 liters using icewater. On standing, a precipitate formed. After standing for a period ofabout 18 hours, the precipitate was recovered by filtration, washed with500 ml. of water and subsequently partitioned between 200 ml. of waterand 50 ml. of methylene dichloride. The suspension, thus formed, wasstirred for about 30 minutes and then filtered. The precipitate wasrecrystallized from aqueous acetone to yield 2-(4-chlorophenyl) 1,3di(4-pyridyl)-2-propanol as pale yellow prisms, melting first at 87 to102 C., resolidifying and melting again at 181 to 183 C.

Example 6 In this example, 24 grams (0.11 mole) of m.-bromobenzoylchloride in 125 ml. of anhydrous terahydrofuran was added, in dropwisefashion over a period of about 75 minutes, to a stirring 0.5 molarsolution of 4-picoly1 lithium. The reaction mixture was maintained at atemperature of about 40 C. during such addition and for a period ofsixty minutes after the addition had been completed. Thereafter, thereaction mixture was stirred at room temperature for a period of about60 minutes. Subsequently, 800 ml. of water was added to the reactionmixture following which the mixture was made acid using 3 N hydrochloricacid. The layers, thus formed, were separated and the organic phase wasextracted twice using 200 ml. of 3 N hydrochloric acid each time. Theacid layers were combined, washed three times using 500 ml. of ethereach time, made alkaline with N sodium hydroxide solution, cooled andre-extracted three times using 200* ml. of methylene chloride each time.The methylene chloride layers were combined, washed three times using200 ml. of water each time and concentrated to an oil. The oil wastriturated three times using 250 m1. of water each time, the layersbeing separated after each washing. The residual oil was thencrystallized by the addition of a small amount of acetone. After tworecrystallizations from benzene, there was obtained 2-(3-bromiophenyl)-1,3-di(4-pyridyl)-2-propano1 in the form of colorless prisms melting at154 to 157 C.

3.0 grams of the 2-(3-bromophenyl)-1,3-di(4-pyridyl)- 2-propanol, whichwas produced as described in the preceding paragraph, was added to 100ml. of methylene chloride and this solution was saturated with hydrogenchloride gas. The solution was concentrated to an oil and crystallizedby the addition of a small amount of ethanol. Recrystallization from anethanol-ether mixture yielded the dihydrochloride salt of2-(3-bromophenyl)- 1,3-di(4-pyridyl)-2-propanol in the form/ of whiteprisms melting at 211 to 212 C.

Example 7 In this example, there was added to a stirring solution of 0.5mole of 4-picolyl lithium, under dry nitrogen, and cooled to atemperature of -30 to 50 C., 34.12 grams (0.2 mole) of p-methoxy benzoylchloride dissolved in 50 ml. of tetrahydrofuran. Addition of the methoxybenzoyl chloride solution was accomplished, in a dropwise fashion, overa period of about one hour. Thereafter, the reaction mixture was stirredat room temperature for a period of about 17 hours, following which thereaction mixture was diluted with 50 ml. of water. The reaction mixturewas extracted three times using 150 ml. portions of 6 N hydrochloricacid each time. The acid extracts were combined, washed three timesusing 150 ml. of ether each time and poured, with stirring, into 300 ml.of concentrated ammonium hydroxide and 500 grams of ice. By thisprocedure there was obtained 2-(4-meth0xyphenyl)-1,3-di(4-pyridyl)-2-propanol in the form of acolorless precipitate. This compound was separated from the solution byfiltration, washed with 500 ml. of water, and recrystallized from anacetone and water mixture. The compound melted. first at 80 C. to 100C., resolidified and melted again at 130 to 133 C. Three subsequentrecrystallizations from an acetone-water mixture yielded pure2-(4-methoxyphenyl)-1,3-di(4-pyridyl)- 2-propanol having a melting pointat 131 to 133 C.

Example 8 In this example, a solution of 116.4 grams (1.25 mole) of4-picoline in 290 ml. of tetrahydrofuran was first prepared. To thissolution, there was added, over a period of about 3 /2 hours at atemperature of about 30 C., 2.28 moles of phenyl lithium in abenzene-ether solution. The mixture was stirred for a period of about 15minutes, following which it was cooled to a temperature of -20 C. Tothis cooled mixture, there was added 116 grams of 3,4,5-trimeth0xybenzoyl chloride dissolved in 260 ml. oftetrahydrofuran. This additionwas accomplished over a period of about 40 minutes, during which timethe mixture was retained at a temperature of approximately -20 C.Stirring was continued an additional sixty minutes after the additionwas complete. Subsequently, 330 ml. of water were added to the reactionmixture, in dropwise fashion, the temperature of the mixture beingmaintained at 30 C. The reaction mixture was then acidified and theaqueous phase was drawn off. The organic layer was extracted three timesusing 200' ml. portions of cold 10% hydrochloric acid each time. Thecombined acid extracts were back washed with 300 ml. of ether and madealkaline by the addition of concentrated ammonium hydroxide. During thisstep, the temperature of the reaction mixture was maintained below about12 C. The precipitate which formed during the neutralization step wasremoved by filtration and partitioned between 600 ml. of methylenechloride and 600 ml. of water. The insoluble product was obtained byfiltration and it was washed first with 200 ml. of cold water andsubsequently two additional times using 200 ml. portions of methylenechloride each time. The product, thus obtained, namely, 1,3 di(4pyridyl) 2 (3,4,5-trimethoxyphenyl)-2- propanol, melted at a temperatureof 151 to 154 C. On recrystallization from ethanol, the compound meltedat a temperature of 168 to 170 C.

Example 9 In this example, 0.2 mole of p-methyl mercapto benzoylchloride, dissolved in 150 ml. of tetrahydrofuran, was added dropwise,over a period of about sixty minutes at a temperature within the rangeof from about -30 to 50 C. under dry nitrogen, to a solution containing0.5 mole of 4-picolyl lithium. The reaction mixture was allowed to stirovernight, following which the reaction mixture was diluted with ml. ofwater. The reaction mixture was thereafter extracted three times usingml. of 6 N hydrochloric acid each time. The acid extracts were combinedand washed three times using 150 ml. of ether each time. Subsequently,the reaction mixture was treated with 500 grams of ice and 300 ml. ofconcentrated ammonium hydroxide, at a temperature of about 0 C., toyield, as a precipitate, 2-(4-methylmercaptophenyl)-1,3-di(4-pyridyl)-2-propanol. The reaction mixture was subsequentlyextracted with methylene chloride, following which the organic phase wasdried over sodium sulfate and reduced, in vacuo, to a gummy residue. Theresidue was, thereafter, washed with ether and continuously extractedfor a period of 48 hours using hexane. There was thus obtained as aninsoluble product,2-(4-methylmercaptophenyl)-1,3-di(4-pyridyl)-2-propanol. This prodnot,after recrystatllization three times from acetone, was obtained in theform of light yellow plates melting at 164.5" to 167 C.

Example 10 In this example, a solution of 39.6 grams (0.2 mole) ofphenyl benzoate in 100 ml. of anhydrous tetrahydrofuran was slowly addedto 0.5 molar solution of 4-picolyl lithium. During this addition,temperature of the reaction mixture rose to a temperature of about 40 C.The reaction mixture was stirred for a period of about one hour,following which it was treated with 800 ml. of water. The aqueous phasewas made acidic by the addition of 350 ml. of 3 N hydrochloric acid.Subsequently,

the mixture was shaken and the layers comprising the two-phase systemwere separated. The organic phase was extracted two times using 200 ml.of 3 N hydrochloric acid each time. The acid layers were then combined,washed three times using 5 00 ml. of ether each time, made alkaline withN sodium hydroxide solution and diluted to a volume of about 4 literswith ice water. The mixture was allowed to stand at room temperature fora period of about 18 hours, during which time a precipitate formed. Theprecipitate was recovered by filtration and washed with 500 ml. ofwater. The product was purified by partitioning between 200 ml. of waterand 50 ml. of methylene chloride. Filtration and subsequentrecrystallization of the product from aqueous acetone yielded 2-phenyl-1,3-di(4-pyridyl)2-propanol melting at 164 to 166 C.

Example 11 In this example, included herein to demonstrate an alternateprocedure for making 2-phenyl-1,3-di(4-pyridyl)- 2-propanol, 4-picolylmagnesium bromide starting material was prepared by the dropwiseaddition of 64.9 grams (0.7 mole) of 4-picoline to a refluxing solutionof ethyl magnesium bromide in 350 ml. of tetrahydrofuran. The ethylmagnesium bromide which was used, was prepared from 17 grams (0.7 mole)of magnesium and 76.3 grams (0.7 mole) of ethyl bromide.

The 4-picolyl magnesium bromide solution, produced as described in thepreceding paragraph, was cooled to a temperature of about 6 C.Thereafter, a solution of 63.7 grams (0.3 mole) of benzyl benzoate in 60mlv of tetrahydrofuran was added, with the temperature of the reactionmixture, during such addition, being maintained within the range ofabout -4 C. to -6 C. When the addition of the benzyl benzoate solutionwas completed, the reaction mixture was allowed to reach roomtemperature, following which it was stirred at such temperature for aperiod of about 18 hours. The Grignard complex was decomposed by theaddition of 375 ml. of 2 N hydrochloric acid and the tetrahydrofuran wasremoved un der reduced pressure. The solution was thereafter madestrongly acidic using hydrochloric acid. Thereafter, the acid solutionwas extracted four times, using 200 ml. of ether each time. The aqueousphase was then made alkaline using sodium hydroxide solution. Thealkaline aqueous phase was filtered and the filtrate was extracted fourtimes using 200 ml. of methylene chloride each time. The organic layerswere then combined, washed two times using 50 ml. of water each time andfinally dried over anhydrous sodium sulfate. The solution was filteredand subsequently evaporated to yield 2-phenyl-1,3-di(4-pyridyl)-2-propanol, which compound, after recrysttallization from aqueousalcohol, melted at 164 to 166 C.

Example 12 In this example, 20 grams of2-phenyl-1,3-di(4-pyridyl)-2-propanol, produced as described in Example1, was dissolved in 3000 cc. of ethyl acetate and saturated with dryhydrogen chloride. The resulting precipitate was filtered and the filtercake dried, in vacuo, at 60 C. over concentrated sulfuric acid. Thecrude cake was then digested for thirty minutes with 1000 cc. ofrefluxing ethyl acetate. Upon filte ing and drying in vacuo at 60 C.,there was obtained Z-phenyl-1,3-di(4-pyridyl)2-propanol dihydrochloride,melting at 227 to 229 C., with decomposition.

Example 13 In this example, 0.2 mole of m-toluic acid chloride dissolvedin 150 ml. of tetrahydrofuran was added in a dropwise fashion over aperiod of about sixty minutes to a stirred solution of 0.5 mole of4-picolyl lithium. This addition was carried out under an atmosphere ofdry nitrogen. with the 4-picolyl lithium solution being maintained at atemperature of from about C. to C. on a bath of dry ice-acetone. Afterabout three hours, the reaction mixture was treated with 100 m]. ofwater, following which it was extracted three times using 150 ml.portions of 6 N hydrochloric acid each time. The acid extract was thenwashed three times, using 150 ml. portions of ether each time.Thereafter, the product was liberated by stirring into a mixture of 500grams of ice and 300 ml. of concentrated ammonium hydroxide. Ice wasadded to the mixture to maintain the temperature thereof at about 0 C.

The mixture, thus obtained, was filtered to obtain a solid,orange-colored product. This product was washed with a mixture of 200ml. of methylene chloride and 400 ml. of water. The solid product, thusobtained, upon recrystallization from an acetone, yielded1,3-di(4-pyridyl)- 2-(o-tolyl)-2-propanol melting at 154 C. to 156 C. aswhite prisms.

Example 14 In this example, 0.2 mole of m-toluic acid chloride dissolvedin 150 ml. of tetrahydrofuran was added, in a dropwise fashion over aperiod of about sixty minutes, to a stirred solution of 0.5 mole of4-picolyl lithium. This addition was carried out under an atmosphere ofdry nitrogen, with the 4-picolyl lithium solution being cooled to atemperature of 30 C. to 50 C. in a bath of dry ice-acetone. After aboutthree hours, the reaction mixture was treated with ml. of water,following which it was extracted three times, using ml. portions of 6 Nhydrochloric acid each time. Thereafter, the acid extracts were combinedand washed three times using 150 ml. portions of ether each time. Theproduct was then liberated by stirring the reaction mixture into amixture of 500 grams of ice and 300 ml. of. concentrated ammoniumhydroxide. lce was added, as needed, to maintain the temperature atabout 0 C.

The basic mixture, thus obtained, was filtered and the solid, whichremained after filtration, was washed with water. The product was thenwashed with 200 ml. of methylene chloride and 400 ml. of water. Uponfiltration, there was obtained 1,3-di(4-pyridyl)-2-m-tolyl)2-pr0- panol,melting point at 146 C. to 149 C. Recrystallization of this product froman acetone yielded 1,3-di(4- pyridyl)-2-(m-tolyl)2-propanol in the formof colorless prisms, melting at 150 C. to 151 C.

Example 15 In this example, 0.2 mole of p-isopropylbenzoic acid chloridedissolved in 150 ml. of tetrahydrofuran was added in a dropwise fashionover a period of about sixty minutes to a stirred solution of 0.5 moleof 4-picolyl lithium. This addition was carried out under an atmosphereof dry nitrogen with the 4-picolyl lithium solution being cooled to atemperature of from about 30 C. to 50 C. On a bath of dry ice-acetone.After about three hours, the reaction mixture was treated with 100 ml.of water, following which it was extracted three times, using 150 ml.portions of 6 N hydrochloric acid each time. The acid extract was thenwashed three times, using 150 ml. portions of ether each time.Thereafter, the product was liberated by stirring into a mixture of 500grams of ice and 300 ml. of concentrated ammonium hydroxide. Ice wasadded to the mixture, as needed, to maintain the temperature thereof atabout 0 C.

The mixture, thus obtained, was filtered to yield a colorlesscrystalline product. Recrystallization of this product from an acetoneyielded 1,3-di(4-pyridyl)2-(4-isopropylphenyl)-2-propanol, as colorlessprisms, melting point at 148 C. to 156 C. Upon recrystallization fromacetone, there was obtained1,3-di(4-pyridyl-2-(4-isopropylphenyl)-2-propanol melting at 163 C. to166 C.

Example 16 In this example, 0.2 mole of 2-fluorobenzoyl chloridedissolved in 150 ml. of tetrahydrofuran was added, in a dropwise fashionover a period of about sixty minutes, to a stirring solution of 0.5 moleof 4-picolyl lithium. This addition was carried out under an atmosphereof 3 dry nitrogen, with the 4-picolyl lithium solution being cooled to atemperature within the range of from about -30 C. to 50 C. in a bath ofdry ice-acetone. The reaction mixture was allowed to stir overnight,following which it was hydrolyzed by the addition of 100 m1. of water.Thereafter, the reaction mixture was extracted three times, using 150ml. portions of 6 N hydrochloric acid each time. The acid extracts werecombined and washed three times, using 150 ml. portions of ether eachtime. The product was liberated by stirirng the washed acid extractsinto a mixture of 500 grams of ice and 300 ml. of ammonium hydroxide.The mixture was filtered to obtain a gum-like, orange solid. Vigorousstirring of this product with 400 ml. of water and 100 ml. of methylenechloride, followed by filtration yielded2(2-fiuorophenyl)-1,3-di(4-pyridyl)-2-propanol melting at 157 C. to 160C. This compound, after recrystallization three times from anacetone-water mixture, was obtained in the form of colorless needlesmelting at 159 C. to 161 C.

Example 17 This example is included herein to demonstrate thepreparation of dosage forms of a compound representative of thecompounds of this invention.

(a) Capsule Formulation: 10 mg. of 2-phenyl-1,3-di-(4-pyridyl)-2-propanol were mixed with 165 mg. of lactose, U.S.P. and 30mg. of corn starch, U.S.P. The mixture was then blended by passingthrough a Fitzpatrick Comminuting Machine with a No. 1A screen withknives forward. The blended powder was, thereafter, returned to themixer and mg. of talc was added thereto and blended therewith. Theproduct was subsequently filled into hard shell gelatin capsules.

(b) Tablet Formulation: 5.10 mg. of 2-phenyl-1,3-di-(4-pyridyl)-2-propanol were mixed with 84.40 mg. of lactose, U.S.P.,10.0 mg. of corn starch and 0.50 mg. of magnesium stearate. The mixturewas blended by passing through a Fitzpatrick Comminuting Machine, filledwith a No. 1A screen with knives forward. The powder was then slugged ona tablet compressing machine, following which the slugs were cornminutedusing a No. 16 screen. The mixture was compressed at a tablet weight of100 mg. using tablet punches having a diameter of approximately fitinch.

(c) Parenteral Formulation: 25 mg. of 2-phenyl-1,3-di(4-pyridyl)-2-propanol was slurried in a small amount of water. To theslurry there was added slowly 1 N hydrochloric acid to pH 3. 0. Thesolution was filtered and allowed to stand for twenty-four hours.Thereafter, the filtrate was filtered through a 02 Selas candle. Thefiltrate was then filled into ampuls, under an atmosphere of nitrogen,which were then sealed. The ampuls were sterilized for twenty minutes ata temperature of 250 F.

Example 18 The activity of an exemplary compound of this invention hasalso been converted clinically as follows:

Nine adult patients were selected from an average population. Thepatients were kept on 6 weeks of constant nitrogen intake prior to thestudy. Each patient was given a loading dose of L-phenylalanine (0.1gram/ kg.) prior to treatment with2-phenyl-1,3-di-(4-pyridyl)-2-propanol and this was repeated at the endof 4 weeks in one patient and 3540 days in the others. The dosage ofZ-phenyl- 1,3-di-(4-pyridyl)-2-propanol for all patients was 100 mg. perday, orally, for 4-6 weeks. Results are as follows:

Part 1 (single patient study).There was a significant lowering of theblood phenylalanine levels after 4 weeks of treatment with2-phenyl-1,3-di-(4-pyridyl)-2 propanol. The decrease ranged from 17.5%at 0 hour to 36.0- 41.5% at 1-4 hours (Table 1A). Even more impressivewas the rise in tyrosine levels following treatment withZ-phenyl-l,3-di-(4-pyridyl)-2propanol, in the range of 3003'50% (Table1B). These results would indicate that an increased conversion ofphenylalanine to tyrosine had taken place, rather than decreasedabsorption or increased elimination.

Part 2.Eight other patients were treated as described above. All showeddecreases in blood phenylalanine levels ranging between 30 and 40%. Sixof these patients, treated with 2-phenyl-1,3-di-(4-pyridyl)-2-propanol,35-40 days, have had detailed chemical data submitted (Table 2). These 6patients showed decreases of phenylalanine in their bloods, butindividual variations were seen and are represented in Table 2. Themeans values for these 6 patients are shown in Table 3 and show a meandecrease in phenylalanine blood levels of around 40%.

All patients had blood counts at the beginning and end of their trials.No decrease in white blood cells were seen. In 4 cases transaminasedeterminations showed normal values at the end of trials. There was noclinical evidence of jaundice, and in those patients who were able tocommunicate, no subjective complaints were reported.

TABLE 1A SINGLE PATI'ENT-PHENYLALANINE LOADING-FEE AND POST TREATMENT2-PHENYL-1,3-DI-(4-PYRIDYL-2-PRO- PANOL MG. DAILY FOR 4 WEEKS) [BloodPhenylalanine (mg. percent)] Pre-Treatment Post Treat- Percent mentChange TABLE 13 BLOOD TYROSINE CONVERSION 2-PHENYL-l,3-DI (4-PY-RIDYL)-2-PROPANOL (100 MG. DAILY FOR 4 WEEKS) Pie-Treatment Post PercentTreatment Change Hours TABLE 2 Patient No. 1--Blood phenylalanine, mg.percent [40 days of drug] 0 hours 17.8 0 hours 15.1 1 hour 32.9 1 hour24.2 2 hours 37.9 2 hours 23.1 3 hours 34.2 3 hours 23.0 4 hours 31.7 4hours 25.0

Patient No. 2-Blood phenylalanine mg. percent [40 days of drug] 0 hours20.3 0 hours 9.3 1 hour 32.9 1 hour 14.2 2 hours 38.3 2 hours 21.9 3hours 38.3 3 hours 21.9 4 hours 34.6 4 hours 21.9

Patient No. 3--Blood phenylalanine mg. percent [35 days of drug] 0 hours22.5 0 hours 12.3 1 hour 28.3 1 hour 21.3 2 hours 30 .0 2 hours 20.5 3hours 35.9 3 hours 22.0 4 hours 34.1 4 hours 23.6

Patient No. 4-Blood phenylalanine mg. percent [35 days of drug] 0 hours24.1 0 hours 13.7 1 hour 34.1 1 hour 21.3 2 hours 34.1 2 hours 21.3 3hours 3 6.6 3 hours 20.5 4 hours 35.9 4 hours 25.9

Patient No. 5Blood phenylalanine mg. percent [35 days of drug] 0 hours46.1 0 hours 38.1 1 hour 91.8 1 hour 53.3 2 hours 95.3 2 hours 57.7 3hours 6 9.7 3 hours 51.1 4 hours 76.7 4 hours 44.4

Patient No. 6-Blood phenylalanine mg. percent [40' days of drug] 0 hours28.9 0 hours 10.0 1 hour 33.7 1 hour 12.1 2 hours 32.6 2 hours 14.6 3hours 46.7 3 hours 15.1 4 hours 53.7 4 hours 19.5

The study indicates that 4-6 Weeks of treatment with2-phenyl-1,3-di-(4-pyridyl)-2-propanol at 100 mg. daily tends to lowerphenylalanine blood levels in chronic adult PKU patients.

We claim:

1. A compound selected from the group consisting of a member having theformula in which X represents a member selected from the groupconsisting of hydrogen, halogen, lower alkyl, lower alkoxy and loweralkylmercapto; and in which n represents the integer 1, with the provisothat where X is alkoxy, n is additionally the integer 3 and saltsthereof with medicinally acceptable acids.

16 fluoro and is in para-position, i.e., the compound 2-(4-fiuorophenyl) -1,3-di(4-pyridyl)-2-propanol.

7. The compound according to claim 1 wherein X is chloro and is inpara-position, i.e., the compound 2-(4-chlorophenyl)-1,3-di(4-pyridyl)-2-propanol.

8. The compound according to claim 1 wherein X is bromo and is inmeta-position, i.e., the compound 2-(3- bromophenyl) -1,3 -di(4-pyridyl-2-propanol.

9. The compound according to claim 1 wherein n is 1 and X is methoxy andis in para-position, i.e., the compound 2-(4-methoxyphenyl)-1,3-di(4pyridy1)-2-propanol.

10. The compound according to claim 1 wherein n is 3 and X is methoxyand is in para and meta-positions, i.e., the compound1,3-di(4-pyri'dyl)-2-(3,4,5-trimethoxyphenyl -2-propanol.

11. The compound according to claim 1 wherein X is methylmercapto and isin para-position, i.e., the compound 2-(4-methylmercaptophenyl)-1,3-di(4-pyridyl) -2- propanol.

12. A salt of a compound according to claim 1 wherein X is hydrogen,i.e., a salt of Z-phenyl-1,3-di(4-pyridyl)-2- propanol with amedicinally acceptable acid.

13. The dihydrochloride according to claim 12, i.e.,2-phenyl-1,3-di(4-pyridy1) -2-propanol dihydrochloride.

14. The compound according to claim 1 wherein X is methyl and is inortho-position, i.e., the compound 1,3- di(4-pyridyl -2- (o-tolyl-2-propanol.

15. The compound according to claim 1 wherein X is methyl and is inmeta-position, i.e., the compound 1,3-

References Cited FOREIGN PATENTS 1/1966 Netherlands.

OTHER REFERENCES Chemical Abstracts, vol. 64, par. 15, 855-15, 856, May1966.

HENRY R. JILES, Primary Examiner.

A. L. ROTMAN, Assistant Examiner.

